Controller for electric motors.



PATENTED JUNE 30, 1903.

E. R. WHITNEY.

CONTROLLER FOR ELECTRIC MOTORS.

APPLICATION FILED MAY 2, 1903.

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Inventor:

Edd Rwhitney.

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No. 732,247. PATENTED JUNE so, 1903. E. R. WHITNEY.

CONTROLLER FOR ELECTRIC MOTORS. APPLIOATiON FILED MAY 2. 1908.

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UNITED STATES Patented June 30, 1903.

PATENT OFFICE.

EDDY R. WHITNEY, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GEN- ERALELECTRIC COMPANY, A CORPORATION OF NEV YORK.

CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent N 0. 732,247, dated June30, 1903.

Application filed May 2, 1903. Serial No. 155,320. (No model.)

To all whont it may concern.-

Be it known that LEDDY R.WHITNEY,a citizen of the United States,residing at Swampscott, in the county of Essex and State ofMassachusetts, have invented certain new and useful Improvements inControllers for Electric Motors, of which the following'is aspecification.

My invention relates to systems of motor control, and more particularlyrelates to the control of a motor or motors operated on a multivoltagesystem of electrical distribution.

In the operation of printing-presses, machine-tools, and the like bymeans of electric motors it is often desirable to obtain a very widerange of speed variation from the motor. Many schemes have beensuggested to accomplish this end without unduly increasing the size ofthe motor. These schemes include hack gears and other unsatisfactorymechanical speed-varying devices. It has also been suggested to operatethe motors on a multivoltage system of distributiont'. 8., to start themotor on mains having a certain potential and then change over to mainshaving a higher potentialand to this latter method of operation mypresent invention is directed.

The object of my invention is to simplify the control of a motor whichis operated on a multivoltage system of electrical distribution, and afurther object is to produce an eflicient and compact controller formaking the proper circuit connections.

In carrying out my invention I employ in a motor-control system acontrolling-switch adapted to connect the motor or motors acrosslow-potential mains to obtain acertain speed, then by varying thestrength of the motorfield increase the motor speed, then connect themotor across higher potential mains and again vary the field strength tofurther increase the speed of the motor or motors.

My invention further consists of improvements in the construction of themotor-controller, which will be hereinafter described, and morespecifically pointed out in the appended claims.

In the accompanying drawings, which illustrate the preferred embodimentof m yinvention, Figure 1 is a front elevation of the controller, thecasing-cover being removed and the pivoted pole-piece swung to one side.Fig. 2 is a sectional plan view of the controller on the line 2 2 ofFig. 1. Fig. 3 is a sectional plan view of the controller on the line 33 of Fig. 1. Figs. at, 5, 6, and 7 are diagrams representing themotor-circuit conneotions corresponding to different positions of thecontroller; and Fig. 8 is a diagrammatic representation of themotor-circuit, the contacts on the cylinder of the controller beingshown in development and the contacts on the fixed disk being shown inplan View.

Referring now to Figs. 1, 2, and 3, A represents the back of thecontroller-casing, the front cover of which is represented by A. Mountedwithin said controller-casing 7o on the shaft 0 is a rotatablecontrolling-cylinder B, carrying contact-segments b. The customary fixedcontact-fingers D are adapted to engage said segments 1) and are mountedon the block d of insulating material, which is fastened to the back ofthe controller-casing. The customary notched disk carried by thecontroller-shaft is indicated by E, and E indicates a spring-pressedlever carrying an antifriction-roller, which is adapted to engage thenotches or serrations in the disk E. Surroundingthe lower end of theshaft 0 is an annular-shaped disk of insulating material upon which aremounted contactpieces,which are arranged concentric to the axis of saidcylinder and are connected to the controlling-resistances in themotor-circuit in a manner to be hereinafter described. This disk ofinsulating material is arranged substantially at right angles to the 0axis of the cylinder B and is preferably supported from the bottom ofthe controller-casing by means of the struts or pillars K, as shown inFig. 1. Mounted directly above the disk K and carried by the cylinder Bare 5 contact-arms H H H The arm H carries the two spring-pressedcontacts 70 and 7c, the arm H carries the spring-pressed contact 10 andthe arm H carries the springpressed contact E The contacts 7c, 70, and kare electrically connected together and are also electrically connected,through the contact-ring b and the contact-finger D mounted on the diskK, to one of the contactfingers D, as will be hereinafter described. Therods h, which pass through openings in the spring-pressed contacts, areadapted to prevent the said contacts from being forced downward beyond apredetermined point by the springs s. The contact 70 is insulated fromthe contacts 7;, 7c, and 70 but it is electrically connected to one ofthe contact-segments on the cylinder B in a manner to be hereinafterdescribed. Mounted concentrically on the lower end of the shaft 0 is theenergizing-coil m of a blow-out magnet,which when energized furnishesthe magnetic flux necessary to efficiently blow out or disrupt the arcs,which tend to form between the contact-fingers D and thecontact-segments b, and also the ares which tend to form between certaincontacts on said disk and the contactarm engaging therewith. The pivotedpolepiece P carries the arc-deflectors S, which embrace thecontact-fingers D when the pivoted pole-piece is in the position shownin Fig. 2, and also has formed thereon a lugp.

' (Shown in full lines in Fig. 1 and in dotted lines in Fig. 3.) Thisprojection or lug p from the pivoted pole-piece P passes under the diskK, as shown in Fig. 3, and forms one'pole-piece of the blow-out magnetfor the starting resistance-contacts 9,10, 11, and 12, which are mountedon the disk K.

Referring now to the diagrammatic representation of the controllingconnections (shown in Figs. 4 to 8, inclusive) the conducting-wires of amultivoltage system of distribution, such as the ordinary three-wiresystem, are represented as follows: the positive wire by the plus-sign,the negative wire by the minus-sign, and the neutral Wire by theplus-minus sign. In Fig. 8 the contact-segments carried by the cylinderB are represented by b to I9 inclusive, and the contact-ring which iselectrically connected to the contactarms H and H is represented by Z).The contact-fingers which are adapted to engage said contact-segmentsare represented by D to D inclusive, and the contact-finger whichengages the ring h is represented by D The motor which is connected inthe controllingcircuit is indicated by M, the armature of said motorbeing designated by a and the field byf. The blow-out magnet, as before,is indicated by m. The customary startingresistance R is connected tothe contactpieces 9, 10, 11, and 12, which are mounted on the disk K.The spring-pressed contact carried by the arm H is adapted to engage thesaid contact-pieces. The resistance R is adapted to be inserted in thefield-circuit and is connected to the contact-strips l3 and 14 and tothe contact-studs 15. The spring-pressed contact Z0, carried by the armH,'is adapted to engage the contact-strip 13, and the contacts 7c and kcarried by the arms H and H, respectively, are adapted to engage thecontact-studs 15 and the contactnected between the positive line-wireand the neutral line-wire of the three-wire system, the contact-fingersD and D being brought into engagement with the contact-segments b and 6While the contact-carrying arms assume the position shown in Fig. 8. Acircuit is thus completed through the motor-armato re as follows: fromthe positive line through the armature a of the motor M, blowoutmagnetcoil m, contact-finger D contactsegment I), conductor 18, contact-arm Hthrough the spring-pressed contact k to-contact-piece 9,starting-resistance R, conductor 21 to the neutral line-wire. A circuitis also completed from the positive line-wire through the field f,conductor 16, contact-strip 13, spring-pressed contact 70, contact-armH, conductor 19 to contact-ring b thence through contact-finger D andconductor 20 to the neutral line-wire. As embodied in the preferred formof controller, the ring Z1 is formed integral with the contact-arms Hand H The circuits just traced are more clearly shown in Fig. 4, whereit will be seen that the starting-resistance R is connected in themotorarmature circuit, while the field f is connected directly acrossthe low-potential mains in shunt to the armature and stafling-resistance.

As the controller-handle is moved forward the starting-resistance R isgradually cut out. A further forward movement of the controller-cylinderbrings the contact-finger D into engagement with the contact-segment bthereby cutting out the starting-resistance entirely and connecting themotorarmature directly across the low-potential mains. Then the contact7t, carried by the arm H, is brought into engagement with thecontact-studs 15 as the contact 70 moves out of engagement with thecontact-strip 13. The resistance R is gradually cut into the motor-fieldcircuit as the contact 70 moves forward over the contact-studs 15. Afterhaving passed over all of the contact-studs 15 the contact engages thestrip 14, and the controller is in its final low-potential position withthe contacts 7c, 70 and 70 idle and the contact-fingers D and D inengagement with the contact-segments b and 19 The circuits for thisposition may be traced as follows: from the positive line-wire throughthe motor-armature a, blow-out magnet-coil m, contact-finger Dcontact-segments b and b contact-finger D to the neutral line-wire andalso from the positive line-wire through IIO the field f, conductor 16,conductor 17, re-

sistance R, contact-strip 14, contact 7c, contact-arm H, conductor 19 tothe neutral wire, as before traced. These connections are more with thefield fin shunt to the motor-armature. A further forward movement of thecontroller-cylinder brings the contact-fingers D and D into engagementwith the contact-segments b and b thereby connecting the motor-armatureacross the high-potential mains or, in other words, across the outsidewires of the three-wire system. In this position of thecontroller-cylinder the contact k carried by the contact-arm II, isbrought into engagement with the contactstud 15, therebyshort-circuiting the resistance R and connecting the motor-fielddirectly across the low-potential mains, as in Fig. 4. The connectionscorresponding to this position are shown in Fig. 6, thestarting-resistance Rremaining out of the motorcircuit and theresistance R being cutout of the field-circuit. The first high-potential position of the controller may correspond to the lastlow-potential position of the controller; but the movement from the lastlowpotential position to the first high-potential position may cause aslight increase in speed, it it is so desired. A further forwardmovement of the controller through its high-potential positions causesthe spring-pressed contact k carried by the contact-arm H, to movesuccessively over the contact-studs 15 and into engagement with thecontact-strip 14 without allowing the contact is to move into engagementwith the contact-strip 13. In the final high-potential position of thecontroller the circuit through the armature of the motor may be tracedas follows: from the positive line-wire through the armature a, blow-outmagnet m, contact-finger D contact-segments b and b contact-finger D tothe negative'line-wire, and the circuit through the field of the motormay also be traced as follows: from the positive line-wire through thefield f, conductors 16 and 17, resistance R, contact-strip 14E,contact-finger k arm H,

conductor 19, contact-ring b contact-finger;

D, conductor 20 to the neutral wire. These connections are clearly shownin Fig. 7,where it will be seen that the starting-resistance is entirelyout out of circuit, also that the armature of the motor is connecteddirectly across the outside line-wires of the system, and themotor-field and the resistance in series therewithIare connected betweenthe positive linewire and the neutral wire, as in Fig. 5.

Although I have shown and described my invention as applied to athree-wire system of distribution, it will be readily seen that l themotor-field to increase the motor speed,

then connect the motor-armature to the highpotential source of supplyand vary the field strength to further increase the speed of the motor.

2. In a motor-control system,a motor,a lowpotential source of onrrent-supply, a relatively high-potential source of current-supply, aresistance, and a controlling-switch operated by a single handle, saidswitch being constructed and arranged to connect the motor-armature tothe low-potential source of supply, then insert the resistance in thefieldcircuit of the motor to increase its speed, then connect themotor-armature to the high-p0 tential source of supply and reinsert theresistance in the field-circuit of the motor to further increase itsspeed.

3. In a motor-control system, a motor, a three-wire system of electricaldistribution, and a controlling-switch constructed and arranged toconnect the motor-armature in circuit between one of the outside wiresof said three-wire system and the neutral wire, then increase the speedof the motor by varying its field strength, then connect themotorarmature between the outside wires of said three-wire system andagain vary the field strength of the motor to further increase itsspeed.

4. In a motor-control system, a motor, a low-potential source of supply,a relatively high-potential source of supply, a startingresistance, afield-resistance, and a controlling-switch adapted to connect themotor-armature in series with said starting-resistance to thelow-potential source of supply, then gradually cut out saidstarting-resistance and insert said field-resistance in thefield-circuit 'to increase the motor speed, then connect saidmotor-armature to the high-potential source of supply simultaneouslycutting the resistance out of the field-circuit and then reinsert saidfield-resistance step by step to further increase the speed of themotor.

5. In a motor-control system, a motor, a low-potential source of supply,a relatively high-potential source of supply, a resistance, and acontrolling-switch constructed and arranged to connect the motor to thelow-potential source, then insert said resistance in the field-circuitstep by step to increase the speed, then connect the motor-armature tothe high-potential source simultaneously cutting said resistance out ofthe field-circuit and leaving the field connected to the low-potentialsource, then reinsert said resistance in the field-circuit step by stepto further increase the motor speed.

6. In a motor-controller, a cylindrical member carryingcontact-segments, contact-fingers adapted to engage therewith, acontactcarrying disk mounted in a plane substantially perpendicular tothe axis of said cylin- 7. In a controller, a rotatable contactcarryingmember, fixed contact-fingers arranged to be engaged thereby, aplurality of fixed contacts arranged concentric to the axis of saidrotatable member, a contact-arm on the rotatable member arranged tosuccessively engage said fixed contacts, and a blow-out magnet for bothsaid contact-fingers and said concentrically-mounted fixed contacts.

8. In a controller, a rotatable contact-carrying member, fixedcontact-fingers arranged to be engaged thereby, a plurality of fixedcontacts arranged concentric to the axis of said rotatable member, acontact-arm on the rotatable member adapted to successively engage saidfixed contacts, and a blow-out magnet having its coil mountedconcentrically with said rotatable member and its poles embracing thecontact-fingers and the concen trically-mounted contacts.

9. In a controller, a rotatable member carrying contacts adapted toconnect the motor to a source of supply, fixed contact-fingers adaptedto be engaged by said rotatable member, a plurality of fixed contactsmounted on an insulating-disk arranged substantially at right angles tothe axis of said rotatable member, said contacts being adapted to varythe motor-circuit, and a single blow-out magnet arranged to disrupt thearcs which tend to form at the contact-fin ers and at the contactsmounted on said disk.

10. In combination, a motor, a resistance, and a motor-controllercomprising a rotatable member carrying contact-segments, a plurality offixed contact-fingers adapted to engage said contact-segments, aplurality of fixed contacts connected to said resistance which isadapted to be inserted step by step in the field-circuit of the motorand a pair of contact-arms carried by said rotatable member which areadapted to engage said fixed contacts, the whole being so constructedand arranged that as the controller is moved forward the rotatablemember will connect the motor to a low-potential source of supply, thenone of said contact-arms will engage said fixed contact-piecessuccessively to insert said resistance in the field of the motor toincrease its speed, then as the controller is moved further the saidcontact-arm will pass out of engagement with said fixed contacts and therotatable member will connect the motor to a higher potential source ofsupply and then the second contact-arm will engage said fixed contactsto reinsert the resistance in the field-circuit and further increase thespeed of the motor.

In witness whereof I have hereunto set my hand this 28d day of April,1903.

E DDY R. WHITNEY.

Witnesses: I

DUGALD MoK. MoKILLoP, JOHN A. MoMANUs.

